Water heater appliance

ABSTRACT

Water heater appliances are provided. A water heater appliance includes a tank, a hot water conduit and a cold water conduit. The water heater appliance further includes a heat pump assembly configured to heat water within the chamber of the tank, and a thermo-electric assembly configured to generate an electrical current. The thermo-electric assembly includes a thermo-electric converter, a working fluid flowable through the thermo-electric converter, and a heat source configured to heat the working fluid within the thermo-electric converter. At least a portion of the electrical current generated by the thermo-electric assembly is flowed to the heat pump assembly to at least partially power the heat pump assembly.

FIELD OF THE INVENTION

The present subject matter relates generally to water heater appliances,and more particularly to water heater appliances which utilizedthermo-electric converters to improve water heater appliance efficiency.

BACKGROUND OF THE INVENTION

Certain water heater appliances include a tank therein. Heatingelements, such as gas burners, electric resistance elements, orinduction elements, heat water within the tank during operation of suchwater heater appliances. In particular embodiments, heat pump assembliesare utilized in water heater appliances, with the condenser of the heatpump acting as the heating element. The heating elements generally heatwater within the tank to a predetermined temperature. The predeterminedtemperature is generally selected such that heated water within the tankis suitable for showering, washing hands, etc.

One goal in water heater appliance design is increasing the energyfactor for the water heater appliance. Energy factor is generallyutilized to compare the energy conversion efficiency of an appliance,such as a water heater appliance. Many typical water heater applianceshave energy factors of less than 0.90. In conventional gas waterheaters, the energy factors are commonly less than 0.60. Recentlydeveloped gas sorption cycle based water heater appliances, whichutilize for example ammonia-water solutions or lithium bromide-watersolutions as a working absorption refrigerant media, generate increasedenergy factors. However, these systems are expensive and complicated,and require an electrical current to maintain operation. In many cases,consumers are reluctant to convert to such systems due to the potentialloss of ability to generate hot water during and due to power losses.

Accordingly, improved water heater appliances are desired. Inparticular, water heater appliances which provide improved energyfactors, and which are not dependent upon mainline electricity foroperation, would be advantageous.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with one embodiment, a water heater appliance isdisclosed. The water heater appliance includes a tank defining achamber, the tank further defining an inlet aperture and an outletaperture. The water heater appliance further includes a hot waterconduit extending through the outlet aperture and in fluid communicationwith the chamber of the tank, the hot water conduit configured fordirecting a flow of water out of the chamber of the tank, and a coldwater conduit extending through the inlet aperture and in fluidcommunication with the chamber of the tank, the cold water conduitconfigured for directing a flow of water into the chamber of the tank.The water heater appliance further includes a heat pump assemblyconfigured to heat water within the chamber of the tank, and athermo-electric assembly configured to generate an electrical current.The thermo-electric assembly includes a thermo-electric converter, aworking fluid flowable through the thermo-electric converter, and a heatsource configured to heat the working fluid within the thermo-electricconverter. At least a portion of the electrical current generated by thethermo-electric assembly is flowed to the heat pump assembly to at leastpartially power the heat pump assembly.

In accordance with another embodiment, a water heater appliance isdisclosed. The water heater appliance includes a tank defining achamber, the tank further defining an inlet aperture and an outletaperture. The water heater appliance further includes a hot waterconduit extending through the outlet aperture and in fluid communicationwith the chamber of the tank, the hot water conduit configured fordirecting a flow of water out of the chamber of the tank, and a coldwater conduit extending through the inlet aperture and in fluidcommunication with the chamber of the tank, the cold water conduitconfigured for directing a flow of water into the chamber of the tank.The water heater appliance further includes a heat pump assemblyconfigured to heat water within the chamber of the tank, and athermo-electric assembly configured to generate an electrical current.The thermo-electric assembly includes a thermo-electric converter, aworking fluid flowable through the thermo-electric converter, and a heatsource configured to heat the working fluid within the thermo-electricconverter. The water heater appliance further includes a heat recoveryvessel disposed at least partially within the chamber, the heat recoveryvessel defining a passage extending between an inlet and an outlet, theinlet configured to receive exhaust fluid from the heat sourcetherethrough. The water heater appliance further includes a condensingconduit connected at an inlet to the outlet of the heat recovery vessel,and an exhaust assembly exterior to the tank, the exhaust assemblyconnected to an outlet of the condensing conduit. At least a portion ofthe electrical current generated by the thermo-electric assembly isflowed to the heat pump assembly to at least partially power the heatpump assembly.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures.

FIG. 1 provides a perspective view of a water heater appliance inaccordance with one embodiment of the present disclosure.

FIG. 2 provides a side cross-sectional view of a water heater appliancein accordance with one embodiment of the present disclosure.

FIG. 3 provides a side cross-sectional view of a water heater appliancein accordance with another embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

FIG. 1 provides a perspective view of a water heater appliance 100according to an exemplary embodiment of the present subject matter.Water heater appliance 100 includes a casing 102. A tank 101 (FIGS. 2and 3) is positioned within casing 102 for heating water therein. Aswill be understood by those skilled in the art and as used herein, theterm “water” includes purified water and solutions or mixturescontaining water and, e.g., elements (such as calcium, chlorine, andfluorine), salts, bacteria, nitrates, organics, and other chemicalcompounds or substances.

Water heater appliance 100 also includes a cold water conduit 104 and ahot water conduit 106 that are both in fluid communication with achamber 111 (FIGS. 2 and 3) defined by tank 101. As an example, coldwater from a water source, e.g., a municipal water supply or a well, canenter water heater appliance 100 through cold water conduit 104 (shownschematically with arrow labeled F_(cool)). From cold water conduit 104,such cold water can enter chamber 111 of tank 101 wherein it is heatedwith heating elements, discussed herein, to generate heated water. Suchheated water can exit water heater appliance 100 at hot water conduit106 (shown schematically with arrow labeled F_(hot)) and, e.g., besupplied to a bath, shower, sink, or any other suitable feature.

Water heater appliance 100 extends longitudinally between a top portion108 and a bottom portion 109 along a vertical direction V. Thus, waterheater appliance 100 is generally vertically oriented. Water heaterappliance 100 can be leveled, e.g., such that casing 102 is plumb in thevertical direction V, in order to facilitate proper operation of waterheater appliance 100. A drain pan 110 is positioned at bottom portion109 of water heater appliance 100 such that water heater appliance 100sits on drain pan 110. Drain pan 110 sits beneath water heater appliance100 along the vertical direction V, e.g., to collect water that leaksfrom water heater appliance 100 or water that condenses on an evaporator(not shown) of water heater appliance 100. It should be understood thatwater heater appliance 100 is provided by way of example only and thatthe present subject matter may be used with any suitable water heaterappliance.

Water heater appliance 100 may further include a controller 134 (seeFIGS. 2 and 3) that is configured for regulating operation of waterheater appliance 100. Controller 134 may be in operative communicationwith various components of the water heater appliances, including, forexample, heating elements and heating assemblies as discussed herein, atemperature sensor as discussed herein, and a control panel 107. Controlpanel 107 may include various displays and input controls for userinterface with the appliance 100. Controller 134 can, for example,selectively activate heating elements in order to heat water withinchamber 102 of tank 101.

Controller 134 includes memory and one or more processing devices suchas microprocessors, CPUs or the like, such as general or special purposemicroprocessors operable to execute programming instructions ormicro-control code associated with operation of water heater appliance100. The memory can represent random access memory such as DRAM, or readonly memory such as ROM or FLASH. The processor executes programminginstructions stored in the memory. The memory can be a separatecomponent from the processor or can be included onboard within theprocessor. Alternatively, controller 134 may be constructed withoutusing a microprocessor, e.g., using a combination of discrete analogand/or digital logic circuitry (such as switches, amplifiers,integrators, comparators, flip-flops, AND gates, and the like) toperform control functionality instead of relying upon software.

Referring now to FIGS. 2 and 3, tank 101 may define an inlet aperture150 and an outlet aperture 152. The inlet and outlet apertures 150, 152may be provided to facilitate the flow of water into and from thechamber 111. For example, cold water conduit 104 may extend throughinlet aperture 150, and hot water conduit 106 may extend through outletaperture 152. Apertures 150, 152 may in exemplary embodiments be defineon an upper portion of the tank 101 along the vertical direction V, suchthat the conduits 104, 106 extend generally vertically into the chamber111.

In exemplary embodiments, appliance 100 may include a temperature sensor160. Temperature sensor 160 may generally sense the temperature in theappliance 100, such as of water in the chamber 111, and may for examplebe in operative communication with the controller 134.

Referring still to FIGS. 2 and 3, the present disclosure is furtherdirected to water heater appliances 100 which provide improved energyfactors. Water heater appliances in accordance with the presentdisclosure advantageously utilize heat pump assemblies andthermo-electric assemblies to heat water in tanks 101 thereof. Thecombined use of heat pump assemblies and thermo-electric assemblies asdiscussed herein advantageously improves the energy factor of theassociated water heater appliance. For example, in some cases, an energyfactor of greater than 1.5, such as greater than 1.7, is attainable inwater heater appliances in accordance with the present disclosure.Further, advantageously, electrical current generated by thethermo-electric assembly of a water heater appliance in accordance withthe present disclosure can be utilized to at least partially power theheat pump assembly and components thereof, as well as the controller 134and various exhaust assembly components as discussed herein. This allowsexemplary water heater appliances in accordance with the presentdisclosure to advantageously remain operational even during, forexample, mainline power outages.

As illustrated, a water heater appliance 100 may include a heat pumpassembly 200. Heat pump assembly 200 and the various components thereofmay, for example, be in communication with the controller 134.Controller 134 may thus be operable to activate and deactivate the heatpump assembly 200 to heat water in the chamber 111. The heat pumpassembly 200 may include, for example, a compressor 202, a condenser204, an expansion device 206 and an evaporator 208. Tubing generallyconnects and extends between these various components of the heat pumpassembly 200, and a refrigerant is flowed through the various componentsof through the tubing between the various components when the heat pumpassembly 200 is active. Any suitable refrigerant may be utilized in aheat pump assembly 200 in accordance with the present disclosure. Oneexemplary refrigerant for use in a heat pump assembly 200 in accordancewith the present disclosure is 1,1,1,2-tetrafluoroethane, also known asR-134A.

As is generally understood, the refrigerant is compressed within thecompressor 202 and then flowed to the condenser 204. Condenser 204 inexemplary embodiments comprises a condenser conduit 210 which defines apassage therethrough, through which refrigerant from the compressor 202is flowed. At least a portion of the condenser conduit 210 is in contactwith the tank 101, such as with an exterior surface of the tank 101. Forexample, as illustrated, at least a portion of the condenser conduit 210may be wrapped around the tank 101, such as in a generally helicalmanner. Heat exchange between the tank 101 (and water therein) and theconduit 210 (and refrigerant therein) may heat the water and cool therefrigerant via emission of heat from the refrigerant.

Condensed refrigerant from the condenser 204 may be flowed to andthrough the expansion device 206, where the pressure of the refrigerantis lowered. In exemplary embodiments as illustrated, expansion device206 is a capillary tube. Alternatively, other suitable expansion devices206 may be utilized. Refrigerant may be flowed from expansion device 206to and through evaporator 208, wherein the refrigerant absorbs heat. Anevaporator fan 212 may be utilized to direct air towards and past theevaporator 208 to facilitate heat exchange to heat the refrigerant. Therefrigerant is then flowed back to the compressor 202 and the cycle isrepeated as required or desired.

As further illustrated, water heater appliance 100 may further include athermo-electric assembly 220 which is generally configured to generatean electrical current. In general, a thermo-electric assembly 220converts heat to electrical energy. Thermo-electric assembly 220 and thevarious components thereof may, for example, be in communication withthe controller 134. Controller 134 may thus be operable to activate anddeactivate the thermo-electric assembly 220 to generate electricity.Assembly 220 may include, for example, a thermo-electric converter 222.Converter 222 generally includes anodes, cathodes, and other componentssuitable for converting heat from a working fluid to electrical energy.In exemplary embodiments, a thermo-electric converter 222 in accordancewith the present disclosure is an alkali-metal thermo-electric converter222. Examples of suitable thermo-electric converters 222 are provided inU.S. Pat. No. 8,865,999 to Rossi et al., entitled “ThermoelectricConverter with Projecting Cell Stack”, issued on Oct. 21, 2014, andwhich is incorporated by reference in its entirety herein.

Assembly 220 may additionally include a working fluid 224, which inexemplary embodiments is an alkali-metal working fluid 224. For example,in exemplary embodiments, working fluid 224 includes sodium. Workingfluid 224 is flowable through the thermo-electric converter 222, whereinelectrical current is generated by such flow therethrough.

Additionally, assembly 220 may include a heat source 226 which isconfigured to heat the working fluid 224 within the thermo-electricconverter 222. Such heating of the working fluid 224 facilitates theconversion of the heat to electrical current within the converter 222.In exemplary embodiments, the heat source 226 is a gas burner, such as anatural gas burner as illustrated. Alternatively, other gas sources suchas propane may be utilized, or other suitable heat sources may beutilized.

As discussed, the thermo-electric assembly 220 generates an electricalcurrent. This electrical current may advantageously be utilized to atleast partially power various other components of the appliance 100.Accordingly, electrical current may be flowed to these components topower them. For example, as illustrated, electrical wires 230 may beconnected between the converter 222 and the various components which arepowered by the generated electrical current. The current may flowthrough the wires to at least partially power the various components.Additionally, one or more transformers 232 may be provided between theconverter 222 and the various components as required to convert thedirect current (“DC”) electricity generated by the converter 222 toalternating current (“AC”) electricity utilized to power the variouscomponents.

In exemplary embodiments as illustrated, at least a portion of theelectrical current generated by the thermo-electric assembly 220 may beflowed to the heat pump assembly 200 to at least partially power theheat pump assembly 200. For example, electrical current may be flowed tothe compressor 202 and to the evaporator fan 212 to at least partiallypower these components of the heat pump assembly 200. Additionally oralternatively, at least a portion of the electrical current generated bythe thermo-electric assembly 220 may be flowed to the controller 134 toat least partially power the controller 134. Additionally oralternatively, at least a portion of the electrical current generated bythe thermo-electric assembly 220 may be flowed to components of anexhaust assembly as discussed herein to at least partially power thecomponents of the exhaust assembly.

In some embodiments, between approximately 10% and approximately 40% ofthe thermal energy from the working fluid 224 can be converted toelectricity. At least a portion of the remaining thermal energy, such asbetween approximately 60% and approximately 90% of the thermal energy,from the working fluid 224 can thus advantageously be utilized to heatwater within chamber 111. For example, in exemplary embodiments,thermo-electric assembly 220 may further include a conduit 240 throughwhich working fluid 224 may flow. Conduit 240 may define a passage 242that extends between an inlet 244 and an outlet 246. The inlet 244 maybe connected to and in fluid communication with the thermo-electricconverter 222 for flowing the working fluid 224 from the thermo-electricconverter 222 into the passage 242. The outlet 246 may be connected toan in fluid communication with the thermo-electric converter 222 forflowing the working fluid 224 from the passage 242 into thethermo-electric converter 222. Accordingly, working fluid 224 may have aclosed-loop flow path between the converter 222 and conduit 240.

The working fluid 224 exiting converter 222 into conduit 240 may berelatively hot working fluid 224 which has been heated by heat source226. The working fluid 224 entering converter 222 from conduit 240 maybe relatively cool working fluid 224 which has undergone heat exchangeand thus emitted heat. For example, in some embodiments, as illustratedin FIG. 2, at least a portion of the conduit 240 may be in contact withthe tank 101, such as with an exterior surface of the tank 101. Forexample, as illustrated, at least a portion of the conduit 240 may bewrapped around the tank 101, such as in a helical manner. Heated workingfluid 224 may be flowed into and through the conduit 240. Heat exchangebetween the tank 101 (and water therein) and the conduit 240 (andworking fluid 224 therein) may heat the water and cool the working fluid224 via emission of heat from the working fluid 224. The cooled workingfluid 224 may then be flowed from conduit 240 into converter 222,wherein the working fluid 224 may again be heated by heat source 226.

In other embodiments, as illustrated in FIG. 3, heat exchange may occurwith an auxiliary assembly rather than directly between the tank 101(and water therein) and the conduit 240 (and working fluid 224 therein).For example, assembly 220 may further include an auxiliary fluid tank250 and an auxiliary conduit 252. An auxiliary fluid 254 may be flowedinto and through the tank 250 and conduit 252. In exemplary embodiments,the auxiliary fluid 254 may be water or another suitable liquid. Conduit252 may define a passage 262 that extends between an inlet 264 and anoutlet 266. The inlet 264 may be connected to and in fluid communicationwith the tank 250 for flowing the auxiliary fluid 254 from the tank 250into the passage 262. The outlet 266 may be connected to and in fluidcommunication with the tank 250 for flowing the auxiliary fluid 254 fromthe passage 262 into the tank 250. Accordingly, auxiliary fluid 254 mayhave a closed-loop flow path between the tank 250 and conduit 252.Notably, in some embodiments, assembly 220 may additionally include apump 256 disposed at least partially in auxiliary fluid tank 250 forflowing auxiliary fluid 254 from tank 250 through inlet 264 into passage262.

A portion of the conduit 240 may be disposed within the auxiliary fluidtank 250 as illustrated or in contact with the auxiliary fluid tank 250(such as with an exterior surface thereof). Heated working fluid 224 maybe flowed into and through the conduit 240. Heat exchange between thetank 250 (and auxiliary fluid 254 therein) and the conduit 240 (andworking fluid 224 therein) may heat the auxiliary fluid 254 and cool theworking fluid 224 via emission of heat from the working fluid 224. Thecooled working fluid 224 may then be flowed from conduit 240 intoconverter 222, wherein the working fluid 224 may again be heated by heatsource 226.

The auxiliary fluid 254 exiting tank 250 into conduit 252 may thus berelatively hot auxiliary fluid 254 which has been heated by such heatexchange. The auxiliary fluid 254 entering tank 250 from conduit 252 maybe relatively cool auxiliary fluid 254 which has undergone heat exchangeand thus emitted heat. For example, in some embodiments, as illustratedin FIG. 3, at least a portion of the conduit 252 may be in contact withthe tank 101, such as with an exterior surface of the tank 101. Forexample, as illustrated, at least a portion of the conduit 252 may bewrapped around the tank 101, such as in a helical manner. Heatedauxiliary fluid 254 may be flowed into and through the conduit 252. Heatexchange between the tank 101 (and water therein) and the conduit 252(and auxiliary fluid 254 therein) may heat the water and cool theauxiliary fluid 254 via emission of heat from the auxiliary fluid 254.The cooled auxiliary fluid 254 may then be flowed from conduit 252 intotank 250, wherein the auxiliary fluid 254 may again be heated by heatexchange between the tank 250 (and auxiliary fluid 254 therein) and theconduit 240 (and working fluid 224 therein).

Referring again to FIGS. 2 and 3, appliance 100 may further include aheat recovery vessel 270. Heat recovery vessel 270 may be disposed atleast partially within the chamber 111, and may thus for example, extendthrough the tank 101 into the chamber 111. Vessel 270 may define apassage 272 extending between an inlet 274 and an outlet 276. The outlet276 may be disposed within the chamber 211. The inlet 274 may beconfigured to receive exhaust fluid (such as exhaust gas) from the heatsource 226 therethrough, and thus for example, may be disposed exteriorto tank 101. For example, inlet 274 may be positioned to receive exhaustfluid from heat source 226 as the exhaust fluid flows pastthermo-electric converter 222, as illustrated. The exhaust fluid mayinclude heat not emitted to converter 222 and working fluid 224 therein.This exhaust fluid may flow through inlet 274 into and through passage272. During such flow through passage 272, heat exchange may occurthrough the vessel 270 between the water in the chamber 211 and theexhaust fluid in the vessel 270, thus heating the water and cooling theexhaust fluid. In some embodiments, vessel 270 may further include fins278 projecting to the chamber 211 to further facilitate such heatexchange.

Exhaust fluid flowing through passage 272 may exit passage 272 throughoutlet 276, and may further flow to exterior to tank 101 to be exhaustedfrom appliance 100. For example, in some embodiments, a condensingconduit 280 may be connected to the vessel 270. Condensing conduit 280may define a passage 282 extending between and inlet 284 and an outlet286. Inlet 284 may be connected to outlet 276, such that exhaust fluidflows from passage 272 into passage 282. The exhaust fluid may furtherflow through condensing conduit 280, wherein further heat exchange mayoccur between the water in the chamber 211 and the exhaust fluid in theconduit 280, thus heating the water and cooling the exhaust fluid. Theoutlet 286 of conduit 280 may be disposed exterior to the tank 101 (andmay further be exterior to the casing 102 as illustrated). Cooledexhaust fluid may exit conduit 280 through outlet 286.

In some embodiments, appliance 100 may further include an exhaustassembly 290 which may be connected to the outlet 286 of the condensingconduit 280. Exhaust assembly 290 may, for example, be disposed exteriorto the tank 101 (and may further be exterior to the casing 102 asillustrated). Exhaust assembly 290 may receive exhaust fluid from thevessel 270 generally, such as from the condensing conduit 280, and mayexhaust the exhaust fluid therefrom. For example, exhaust assembly 290may include a housing 296, vent 298, exhaust fan 292 and drain 294(which may for example be a preexisting drain of a home or office towhich the appliance is coupled). Exhaust fluid may flow from outlet 286into housing 296. Gaseous components of the exhaust fluid may flowthrough vent 298 to be exhausted, and this flow may be encouraged by fan292. Liquid components of the exhaust fluid may flow through drain 294to be exhausted. Notably, in exemplary embodiments, at least a portionof the electrical current generated by the thermo-electric assembly 220may be flowed to fan 292 to at least partially power the fan 292.

As discussed, water heater appliances 100 in accordance with the presentdisclosure advantageously operate with improved energy factors. Inparticular, the combined use of heat pump assemblies and thermo-electricassemblies as discussed herein, and in particular the use of theelectrical current generated by the thermo-electric assemblies to powervarious other components of the water heater appliances 100,advantageously improves the energy factor of the associated water heaterappliance. Additionally, the use of heat recovery vessels 270 and othercomponents as disclosed herein advantageously provides further increasedand efficient heat exchange, thus further contributing to the improvedenergy factors of water heater appliances in accordance with the presentdisclosure.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A water heater appliance, comprising: a tankdefining a chamber, the tank further defining an inlet aperture and anoutlet aperture; a hot water conduit extending through the outletaperture and in fluid communication with the chamber of the tank, thehot water conduit configured for directing a flow of water out of thechamber of the tank; a cold water conduit extending through the inletaperture and in fluid communication with the chamber of the tank, thecold water conduit configured for directing a flow of water into thechamber of the tank; a heat pump assembly configured to heat waterwithin the chamber of the tank; and a thermo-electric assemblyconfigured to generate an electrical current, the thermo-electricassembly comprising an thermo-electric converter, a working fluidflowable through the thermo-electric converter, and a heat sourceconfigured to heat the working fluid within the thermo-electricconverter, wherein at least a portion of the electrical currentgenerated by the thermo-electric assembly is flowed to the heat pumpassembly to at least partially power the heat pump assembly.
 2. Thewater heater appliance of claim 1, wherein the working fluid is analkali-metal working fluid.
 3. The water heater appliance of claim 1,wherein the thermo-electric assembly further comprises a conduit, theconduit defining a passage extending between an inlet and an outlet forflowing the working fluid therethrough, the inlet in fluid communicationwith the thermo-electric converter for flowing the working fluid fromthe thermo-electric converter into the passage, the outlet in fluidcommunication with the thermo-electric converter for flowing the workingfluid from the passage into the thermo-electric converter.
 4. The waterheater appliance of claim 3, wherein a portion of the conduit is incontact with the tank.
 5. The water heater appliance of claim 4, whereinthe portion of the conduit is generally helically wrapped around thetank.
 6. The water heater appliance of claim 3, wherein thethermo-electric assembly further comprises an auxiliary fluid tank andan auxiliary conduit, the conduit defining a passage extending betweenan inlet and an outlet for flowing an auxiliary fluid therethrough, theinlet in fluid communication with the auxiliary fluid tank for flowingthe auxiliary fluid from the auxiliary fluid tank into the passage, theoutlet in fluid communication with the auxiliary fluid tank for flowingthe auxiliary fluid from the passage into the auxiliary fluid tank. 7.The water heater appliance of claim 6, wherein a portion of theauxiliary conduit is in contact with the tank.
 8. The water heaterappliance of claim 1, wherein the heat source is a gas burner.
 9. Thewater heater appliance of claim 8, wherein the gas burner is a naturalgas burner.
 10. The water heater appliance of claim 1, furthercomprising a heat recovery vessel disposed at least partially within thechamber, the heat recovery vessel defining a passage extending betweenan inlet and an outlet, the inlet configured to receive exhaust fluidfrom the heat source therethrough.
 11. The water heater appliance ofclaim 10, further comprising a condensing conduit connected at an inletto the outlet of the heat recovery vessel.
 12. The water heaterappliance of claim 11, further comprising an exhaust assembly exteriorto the tank, the exhaust assembly connected to an outlet of thecondensing conduit.
 13. The water heater appliance of claim 12, whereinthe exhaust assembly comprises an exhaust fan and a vent.
 14. The waterheater appliance of claim 13, wherein at least a portion of theelectrical current generated by the thermo-electric assembly is flowedto the exhaust fan to at least partially power the exhaust fan.
 15. Thewater heater appliance of claim 1, further comprising a controller, andwherein at least a portion of the electrical current generated by thethermo-electric assembly is flowed to the controller to at leastpartially power the controller.
 16. A water heater appliance,comprising: a tank defining a chamber, the tank further defining aninlet aperture and an outlet aperture; a hot water conduit extendingthrough the outlet aperture and in fluid communication with the chamberof the tank, the hot water conduit configured for directing a flow ofwater out of the chamber of the tank; a cold water conduit extendingthrough the inlet aperture and in fluid communication with the chamberof the tank, the cold water conduit configured for directing a flow ofwater into the chamber of the tank; a heat pump assembly configured toheat water within the chamber of the tank; a thermo-electric assemblyconfigured to generate an electrical current, the thermo-electricassembly comprising an thermo-electric converter, a working fluidflowable through the thermo-electric converter, and a heat sourceconfigured to heat the working fluid within the thermo-electricconverter; a heat recovery vessel disposed at least partially within thechamber, the heat recovery vessel defining a passage extending betweenan inlet and an outlet, the inlet configured to receive exhaust fluidfrom the heat source therethrough; a condensing conduit connected at aninlet to the outlet of the heat recovery vessel; and an exhaust assemblyexterior to the tank, the exhaust assembly connected to an outlet of thecondensing conduit, wherein at least a portion of the electrical currentgenerated by the thermo-electric assembly is flowed to the heat pumpassembly to at least partially power the heat pump assembly.
 17. Thewater heater appliance of claim 16, wherein the thermo-electric assemblyfurther comprises a conduit, the conduit defining a passage extendingbetween an inlet and an outlet for flowing the working fluidtherethrough, the inlet in fluid communication with the thermo-electricconverter for flowing the working fluid from the thermo-electricconverter into the passage, the outlet in fluid communication with thethermo-electric converter for flowing the working fluid from the passageinto the thermo-electric converter.
 18. The water heater appliance ofclaim 16, wherein the exhaust assembly comprises an exhaust fan and avent.
 19. The water heater appliance of claim 18, wherein at least aportion of the electrical current generated by the thermo-electricassembly is flowed to the exhaust fan to at least partially power theexhaust fan.
 20. The water heater appliance of claim 16, furthercomprising a controller, and wherein at least a portion of theelectrical current generated by the thermo-electric assembly is flowedto the controller to at least partially power the controller.